SOMBA K'E/YELLOWKNIFE - Arsenic levels in Baker Creek are 10 times the acceptable level for drinking water and 20 times the acceptable level for protection of aquatic life, according to samples collected at the Giant Mine site just over two weeks ago.

Water samples taken from Baker Creek two weeks ago show arsenic levels 10 times the acceptable level for drinking water after the stream overflowed into a tailings pond earlier this month. - Ian Vaydik/ NNSL photo

That, combined with low water temperatures and water cloudiness, could hinder or delay Arctic grayling spawning in the creek, according to Public Works and Government Service Canada.

"It is a contaminated site," said Randal Cripps, regional director general for Public Works, although communications officials with the department insist levels aren't "acutely toxic" to fish or plankton.

Hilary Machtans of Golder Associates conducted the sampling, which showed arsenic levels were highest upstream, just off of

Vee Lake Road.

Levels were lower where the creek feeds into Yellowknife Bay, but still seven times higher than acceptable levels for drinking water and 14 times higher than acceptable levels for protection of aquatic life.

"The creek is continuing to improve in its quality," she said, "but it has not yet returned to (past levels.)"

The city of Yellowknife is currently toying with the idea of changing the city's drinking water source to Yellowknife Bay, although its water treatment plant would be outfitted with an arsenic treatment system.

"We're not expecting that people would try and drink the water from the stream, because it would never be safe for that," Henry Westermann, director of the Giant Mine project for Public Works Canada, said in response to concerns that the public could be put at risk.

"If there was a need to put a sign up for any safety reasons we would certainly do that. At this point I don't think we're seeing a safety risk that we would need to inform the public about."

Machtans echoed Westermann's statement and added, "It's my general understanding that the general public in Yellowknife do not drink

this water regardless."

She said there was no reason the public should stop fishing in that portion of Yellowknife Bay, but that it might be a good idea to post a sign saying snorkeling is unsafe.

Officials made the decision to test the creek's water after an ice dam caused it to overflow over an old mine road and into a tailings pond May 14.

The creek was redirected back into its channel May 17 after crews excavated the ice that was causing the blockage.

Cripps said that Public Works will continue to monitor the situation, and will release up-to-date lab findings when they receive the newest results back.

In the meantime, they have created a fish monitoring program to watch for when and if fish return, and whether their activities are normal.